Exercise prescription variables predict reductions in pain intensity in adults with chronic low back pain: secondary analysis of a randomised controlled trial

Objectives

The relationship between exercise training variables and clinical outcomes in low back pain (LBP) is unclear. The current study aimed to explore the relationship between exercise training parameters and pain intensity in individuals with chronic LBP.

Methods

This study is a secondary analysis of a previously reported randomised controlled trial comparing the effects of general strength and conditioning to motor control exercises and manual therapy. This secondary analysis includes adults with chronic LBP (n=20) randomised to the general strength and conditioning programme only. Primary outcomes of this analysis were exercise training parameters (time under tension, rating of perceived exertion (RPE), session duration, session-RPE and training frequency) and pain intensity (0-100 mm visual analogue acale) measured every 2 weeks from baseline to 6 months follow-up. Linear mixed models with random effects (participants) and allowance for heterogeneity of variance (study date) were used to determine the association between pain intensity and training parameters over time.

Results

Mean (95% CI) pain intensity decreased over time from baseline to 6 months follow-up by 10.7 (2.8 to 18.7) points (p=0.008). Over the 6-month intervention, lower pain intensity was associated with higher RPE (β (95% CI) -27.168 (-44.265 to -10.071), p=0.002), greater time under tension (-0.029 (-0.056 to -0.001), p=0.040) and shorter session duration (1.938 (0.011 to 3.865), p=0.049).

Conclusion

During 6 months of general strength and conditioning, lower pain intensity was associated with higher participant-reported training intensity, greater volume and shorter session duration. To ensure positive outcomes to exercise training, these variables should be monitored on a short-term basis.

Trial registration number

ACTRN12615001270505.

Lumbar spine bone mineral adaptation: cricket fast bowlers versus controls

Elite adult male fast bowlers have high lumbar spine bone mineral, particularly on the contralateral side to their bowling arm. It is thought that bone possesses its greatest ability to adapt to loading during adolescence, but it is unknown at what age the greatest changes in lumbar bone mineral and asymmetry develops in fast bowlers.

Objectives

This study aims to evaluate the adaptation of the lumbar vertebrae in fast bowlers compared to controls and how this is associated with age.

Methods

91 male fast bowlers and 84 male controls aged 14-24 years had between one and three annual anterior-posterior lumbar spine dual-energy-X-ray absorptiometry scans. Total (L1-L4) and regional ipsilateral and contralateral L3 and L4 (respective to bowling arm) bone mineral density and content (BMD/C) were derived. Multilevel models examined the differences in lumbar bone mineral trajectories between fast bowlers and controls.

Results

At L1-L4 BMC and BMD, and contralateral BMD sites, fast bowlers demonstrated a greater negative quadratic pattern to their accrual trajectories than controls. Fast bowlers had greater increases in BMC in L1-L4 between 14 and 24 years of 55% compared with controls (41%). Within vertebra, asymmetry was evident in all fast bowlers and increased by up to 13% in favour of the contralateral side.

Conclusions

Lumbar vertebral adaptation to fast bowling substantially increased with age, particularly on the contralateral side. The greatest accrual was during late adolescence and early adulthood, which may correspond with the increasing physiological demands of adult professional sport.

The epidemiology of back injuries in elite Gaelic football athletes: An 8-year prospective study

OBJECTIVES

To describe the epidemiology of back injury in elite male Gaelic football athletes between 2008 and 2016.

DESIGN

Prospective cohort study.

SETTING

Injury data from the National GAA Injury Surveillance Database.

PARTICIPANTS

Elite male Gaelic football athletes.

MAIN OUTCOME MEASURES

Incidence of injury as a rate per 1000 h of exposure.

RESULTS

38 datasets were analysed. Out of a total of 1606 time-loss injuries, 76 were back injuries (4.73%, 95% CI 3.80%-5.88%). The incidence of back injuries in match play was 1.72 (CI 95% 1.21 to 2.45) and in training was 0.2 (CI 95% 0.14 to 0.28) injuries per 1000 h of exposure. The majority of back injuries (63.16%, CI 95% 51.93-73.12) were new, as opposed to recurrent (35.53% CI 95% 25.7-46.74). Most back injuries were acute (51.32%, CI 95% 40.29-62.22), compared to chronic (31.58%, CI 95% 22.23-42.7) or overuse (11.84%, CI 95% 6.36-21.00). The majority of back injuries occurred during non-contact player activities (n = 60, 78.94% CI 95% 68.50-86.60).

CONCLUSIONS

Back injury rates in Gaelic football are similar to soccer and Australian football but less than rugby union. Further research is needed to understand the factors leading to the onset and recurrence of back injury in Gaelic football athletes.

Diagnostic accuracy of MRI for identifying posterior element bone stress injury in athletes with low back pain: a systematic review and narrative synthesis

Objective

To investigate the diagnostic accuracy of MRI for identifying posterior element bone stress injury (PEBSI) in the athletic population with low back pain (LBP).

Study Design

A systematic review searched for published sources up until July 2020. Eligibility criteria: prospective cohort design, MRI diagnosis, adolescents/young adults, chief symptoms of LBP, PEBSI as the clinical diagnosis and SPECT-CT as reference standard. Risk of bias and overall quality were assessed using QUADAS-2 and GRADE, respectively. A narrative synthesis was conducted.

Results

Four studies were included, with three included in the quantitative synthesis. Compared with SPECT-CT, two studies involving MRI demonstrated sensitivity and specificity of 80% and 100%, and 88% and 97%, respectively. Compared with CT, one study involving MRI demonstrated sensitivity and specificity of 97% and 91%, respectively. Risk of bias was moderate to high although consistency across studies was noted.

Conclusion

Findings support further research to consider MRI as the modality of choice for diagnosing PEBSI. MRI was consistent with SPECT-CT for ruling-in PEBSI, but the clinical value of cases where MRI had false negatives remains uncertain due to possible over-sensitivity by SPECT-CT.

PROSPERO registration number

CRD42015023979.

Modeling and simulation of the impact behavior of soft polymeric-foam-based back protectors for winter sports

OBJECTIVES

Winter sports are high-energy outdoor activities involving high velocities and acrobatic maneuvers, thus raising safety concerns. Specific studies on the impact mechanics of back protectors are very limited. In this study analytical and numerical models are developed to rationalize results of impact experiments and propose new design procedures for this kind of equipment.

DESIGN

Different soft-shell solutions currently available on the market are compared. In particular, the role of dynamic material constitutive properties and of environmental temperature (which affects mainly material stiffness) on energy absorption capability are evaluated.

METHODS

Starting from dynamic mechanical-thermal characterization of the closed-cell polymeric foams constituting the protectors, we exploited analytical modeling and Finite Element Method simulations to interpret experimental data from drop weight impact test and to characterize protectors at different temperatures and after multiple impacts.

RESULTS

The temperature and frequency dependent properties of these materials characterize their impact behavior. Modeling results are in good agreement with impact tests. Results demonstrate how ergonomic soft-shell solution provides an advantage with respect to traditional hard-shell in terms of impact protection. Moreover, it can maintain nearly unaltered its protective properties after multiple impacts on the same point.

CONCLUSIONS

The coupled analytical-simulation approach here presented could be extensively used to predict the impact behavior of such equipment, starting from material characterization, allowing to save costs and time for physical prototyping and tests for design and optimization.

Who will have Sustainable Employment After a Back Injury? The Development of a Clinical Prediction Model in a Cohort of Injured Workers

Purpose Our objective was to develop a clinical prediction model to identify workers with sustainable employment following an episode of work-related low back pain (LBP). Methods We used data from a cohort study of injured workers with incident LBP claims in the USA to predict employment patterns 1 and 6 months following a workers' compensation claim. We developed three sequential models to determine the contribution of three domains of variables: (1) basic demographic/clinical variables; (2) health-related variables; and (3) work-related factors. Multivariable logistic regression was used to develop the predictive models. We constructed receiver operator curves and used the c-index to measure predictive accuracy. Results Seventy-nine percent and 77 % of workers had sustainable employment at 1 and 6 months, respectively. Sustainable employment at 1 month was predicted by initial back pain intensity, mental health-related quality of life, claim litigation and employer type (c-index = 0.77). At 6 months, sustainable employment was predicted by physical and mental health-related quality of life, claim litigation and employer type (c-index = 0.77). Adding health-related and work-related variables to models improved predictive accuracy by 8.5 and 10 % at 1 and 6 months respectively. Conclusion We developed clinically-relevant models to predict sustainable employment in injured workers who made a workers' compensation claim for LBP. Inquiring about back pain intensity, physical and mental health-related quality of life, claim litigation and employer type may be beneficial in developing programs of care. Our models need to be validated in other populations.

The effects of a free-weight-based resistance training intervention on pain, squat biomechanics and MRI-defined lumbar fat infiltration and functional cross-sectional area in those with chronic low back

Background

Low back pain is one of the most prevalent musculoskeletal conditions in the world. Many exercise treatment options exist but few interventions have utilised free-weight resistance training. To investigate the effects of a free-weight-based resistance training intervention on pain and lumbar fat infiltration in those with chronic low back pain.

Methods

Thirty participants entered the study, 11 females (age=39.6±12.4 years, height=164 cm±5.3 cm, body mass=70.9±8.2 kg,) and 19 males (age=39.7±9.7 years, height=179±5.9 cm, body mass=86.6±15.9 kg). A 16-week, progressive, free-weight-based resistance training intervention was used. Participants completed three training sessions per week. Participants completed a Visual Analogue Pain Scale, Oswestry Disability Index and Euro-Qol V2 quality of life measure at baseline and every 4 weeks throughout the study. Three-dimensional kinematic and kinetic measures were used for biomechanical analysis of a bodyweight squat movement. Maximum strength was measured using an isometric mid-thigh pull, and lumbar paraspinal endurance was measured using a Biering-Sorensen test. Lumbar paraspinal fat infiltration was measured preintervention and postintervention using MRIs.

Results

Postintervention pain, disability and quality of life were all significantly improved. In addition, there was a significant reduction in fat infiltration at the L3L4 and L4L5 levels and increase in lumbar extension time to exhaustion of 18%.

Conclusions

A free-weight-based resistance training intervention can be successfully utilised to improve pain, disability and quality of life in those with low back pain.

Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more than acupuncture alone: a randomised cross-over experiment

BACKGROUND

High-quality clinical evidence suggests that although acupuncture appears superior to usual care in the management of chronic low back pain, there is little meaningful difference between true and sham acupuncture. This suggests that the benefits of acupuncture are mediated by the placebo response. An alternative explanation is that sham acupuncture is an active treatment and shares a mechanism of action with traditionally applied acupuncture. One plausible candidate for this mechanism is improvement in self-perception mediated through the sensory discrimination-like qualities of acupuncture. We aimed to compare the effects of acupuncture with a sensory discrimination training component to acupuncture without.

METHODS

25 people with chronic low back pain were enroled in a randomised cross-over experiment. We compared the effect of acupuncture delivered when sensory discrimination is optimised to acupuncture delivered when it is not, on movement-related back pain immediately after each intervention.

RESULTS

We found that the average pain intensity after participants had received acupuncture with sensory discrimination training (2.8±2.5) was less than when they received acupuncture without sensory discrimination training (3.6±2.0). This difference was statistically significant (after adjustment; mean difference=-0.8, 95% CI -1.4 to -0.3; p=0.011).

CONCLUSIONS

Our findings are consistent with the idea that acupuncture may offer specific benefit that is not dependent on precisely where the needles are inserted so much as that the patient attends to where they are inserted. If so, the location of the needles might be better focused on the painful area and the need for penetration of the skin may be mitigated.

Two-level traumatic lateral lumbar fracture and dislocation in a heavy equipment operator: a case report

OBJECTIVE

Lumbar fracture-dislocations are rare and invariably due to high-energy trauma. The purpose of this study is to report the surgical management of a man with lateral lumbar dislocations in 2 noncontiguous lesions.

CLINICAL FEATURES

A 49-year-old Asian man was crushed by a bulldozer. The patient was transported to a major medical center where he was found to be conscious, and the primary spinal injuries were fracture-dislocation of L1-L2 and L4-L5. His preoperative neurologic status showed a partial paraparesis to all motor groups of the lower extremities bilaterally. His radiological and operative findings showed a rupture of the thoracolumbar fascia and latissimus dorsi muscle, left L1-L2 dislocated facet, right L4-5 facet fracture, and dural tear.

INTERVENTION AND OUTCOME

The patient underwent a posterior reduction, decompression, instrumentation, and fusion surgery from T12 to S1 with autologous bone graft and pedicle screw instrumentation. Postoperatively, his neurologic status improved, allowing him to be ambulatory using a Lofstrand crutch with improved lumbosacral alignment being well maintained. Two weeks postoperatively, the patient regained voluntary bowel and bladder function. At the 1-year follow-up evaluation, his motor power was full in the left leg; however, sensation to pin prick remained lost on the right L5 and S1 distributions. He continued to ambulate using a Lofstrand crutch.

CONCLUSION

Lateral lumbar fracture-dislocation at 2 noncontiguous levels is an unusual injury that results from high-energy trauma. Prompt recognition of the injuries, reduction of the fracture-dislocations, and posterior stabilization are recommended for neural decompression, spinal alignment, and long-term stabilization.

Critical factors for the prevention of low back pain in elite junior divers

BACKGROUND/AIM

During competitive diving, divers jump up from 1 to 3 m springboards or 5 to 10 m platforms and dive into the water. The impact forces are very large in the water entry phase, and, as such, microtraumatic injuries are common due to the tremendous physical stress placed on the diver. Low-back pain (LBP) is the most frequently reported symptom in divers. This study aimed to extract possible risk factors related to LBP from physical and technical characteristics in Japanese elite junior divers.

METHODS

Eighty-three elite junior divers (42 men and 41 women) in Japan were included in this study. LBP was assessed by a questionnaire, interview and physical examination during a national training camp. Morphological data, physical fitness and diving skills were also evaluated. The factors related to LBP were extracted by using logistic-regression analysis and the forward-selection method (likelihood ratio).

RESULTS

A total of 37.3% (31 reports) of back pain occurred in the lumbar region. Shoulder flexibility (OR 0.919; 95% CI 0.851 to 0.992) and age (OR 0.441; 95% CI 0.239 to 0.814) were recognised as factors related to LBP in male-elite junior divers, whereas only age (OR 0.536; 95% CI 0.335 to 0.856) was a factor in female-elite junior divers.

CONCLUSIONS

Our results suggest that shoulder flexibility is important for preventing LBP in elite-male junior divers, since they require full shoulder flexion during the water entry phase. Limited shoulder flexibility could cause lumbar hyperextension when adjusting for the angle of water entry.